1. Field of Invention
The present invention relates to a mixer; and more particularly relates to an inline mixer used to mix one or more chemicals with a process flow media.
2. Description of Related Art
Inline mixers, such as that shown in FIGS. 1–3, are used to mix one or more chemicals with a process flow media.
FIG. 1 shows a casing 10 of one such known inline mixer having an inlet 12 for receiving the chemical and process flow media for mixing and an outlet 14 for providing a mixture thereof. The chemical is injected into the process flow upstream of the inline mixer. In FIGS. 1 and 3, the casing 10 has a stationary vane 18 that is a continuous vane arranged around and on an inner surface 10a of the casing 10 at an oblique angle relative to the direction of flow of the chemical and process flow media.
FIG. 2 shows a rotor 16 having a set of three rotary vanes 16a, 16b, 16c that is inserted into the casing 10. The stationary vane 18 interacts with the set of three rotating vanes 16a, 16b, 16c to create turbulence and shear to promote the mixing of the chemical and the process flow media. The  vane configuration shown in FIGS. 1 and 3 provides the high shear and turbulence required for good mixing of chemicals that have been added upstream of the chemical mixer. However, the angled stationary vane 18 as shown in FIGS. 1 and 3 allows some portion of the chemical flow to bypass the mixing zone by flowing under or over the combined rotating/stationary vane system. This flow bypass reduces the mixing effectiveness, causing non-uniform concentrations of chemical(s), resulting in the need to add additional chemicals or accept less than desired mixing performance.
In comparison, Roll (U.S. Pat. No. 5,575,559) discloses a mixer for mixing multi-phase fluids having stationary casing vane(s) at an angle oblique to both the process flow and the axis of the rotor, as well as having a transverse vane or rib placed parallel to the axis of rotation of the rotary vanes, and perpendicular to the process flow media. However this mixer design does not mix well, i.e. the “mixing effectiveness” is not high enough.
In view of this, there is a need in the industry for an improved inline mixer architecture to that known in the art. 